The typical platform framing technique, which is also the most common light framing construction technique (in USA, Canada, Australia, UK) requires the interpretation of blueprints, often designed using a CAD software, and the selection, measurement, marking, cut and assembly of many components, (as studs) that need to be spaced at specific distances. All the work is made on the construction site where weather may impede construction.
This phase requires the presence on site of highly qualified personnel, it is the most complex and it is subject to errors caused by incorrect interpretation of the drawings or by human error in the marking process or cutting of the components. Moreover, after having correctly positioned the various components to the ground, components as studs typically are repositioned elsewhere for cutting and then placed back in position, an operation which requires additional time.
There are alternatives to traditional platform framing on-site construction.
The most known and used is the off-site prefabrication of entire walls or sections of walls, floors, and trusses, which are then transported to the construction site.
Another system, typically used for kit-homes, requires to process every single stud, plate, joist or other components one at a time, cutting and marking them, then packing and shipping all to the construction site.
Other less known patented systems require the prefabrication of collapsible light metal frames which are then opened and installed on-site, where the vertical components are hinged with the horizontal components. Sometimes even the studs are collapsible (example U.S. Pat. No. 6,318,044 B1).
The pre-prefabrication in a factory of complete walls and floors (framework and sheathing) are well known and generally used when there is the need to build on a very short timeframe, on remote sites or with adverse climate. In those cases these system is competitive compared to the traditional platform framing on-site construction but usually they are not very cost-effective and therefore less used.
For the prefabrication of entire walls and ceiling usually the money saved thanks to the use of better systems within the factory and thanks to a faster installation on-site is often compensated by the fixed costs of the facility where the walls are manufactured, the cost of the equipment used, which is not fully automated, therefore it still requires extensive use of labor in the factory, and transportation costs, much higher than the simple transportation of the lumber needed for traditional on-site construction (which take up only about 25% of prefabricated walls and floors volume during transportation). Furthermore there is the cost of temporary indoor storage space for finished walls and sometimes the crane cost for the installation on-site.
In addition most of the times contractors does not own the factory, for the manufacturing of walls and floors, and the crane needed for the installation on-site, so they need to pay third-party suppliers, reducing their profit.
About kit-houses, with all the elements pre-cut in an off-site facility, the transportation cost is not substantially different, but the costs are increased by the need to cut, number, mark and make a schedule of all the components, one by one, and by the fact that on the construction site somebody need to interpret the drawings and the schedule of all the singular components and then find them. This can be quite complex and time consuming, making this system usually not competitive compared to the traditional on-site marking & cutting of the components, especially for the construction of a single home.
About the patented collapsible light frames hitherto known, if they are in production they are really little used. Probably the drawback of this systems can be the high production cost, due to a higher number of industrial processes required, the greater amount of material required and the transportation cost, more competitive compared to other known types but still greater than the transportation cost of the individual, not yet assembled, components. Moreover, often this systems work only for light gauge metal frames, still far less used than wood.